1. Field of the Invention
This invention pertains in general to the field of bone fixation devices and in particular to an intramedullary nail which may be used for reconstruction of fractures of the femoral or the tibia bones.
2. Description of the Prior Art
Closed transverse fractures in the middle one third of the femur and/or the tibia have historically been reconstructed using an intramedullary nail. For these types of simple fractures, the prior art intramedullary nail comprising an elongated hollow rod either slotted or unslotted have successfully been used to reconstruct such broken bones. Usually, and more so in the present prior art, a locking nail has been utilized. A locking nail involves the use of transverse screws passing through the bone and the intramedullary nail at both of the proximal and distal locations of the tibia or the femur. Such locking provisions provide for proper alignment of the bones as well as provide for the proper length fixation of the bones after the break.
On the other hand, comminuted fractures, segmental fractures, fractures with bone loss, and rotationally unstable fractures of these bones are much more difficult to treat using the prior art intramedullary nails. With any of these types of fractures, there is the distinct possibility that non-union, rotation and displacement of bone fragments may result. Improper angularity may include transverse angularity where the broken portions of the bone are transversely offset relative to each other; axial angularity involves improper alignment of the axial centerline of the broken portions of the bone; and, rotational angularity involves improper rotational alignment of one broken portion of the bone relative to the other portion of the bone. All of these degrees of angularity must be properly aligned in order to properly reconstruct a broken femur or tibia.
In the prior art intramedullary nails, the locking provision of the same provides the only means to assure proper angularity and length fixation of reconstructed bones. In this regard, as previously stated, the prior art intramedullary nails are provided with one or more through transverse holes at each end of the nail for purposes of inserting a screw fastener therethrough after the intramedullary nail has been fitted within the broken portions of the bones. Once the intramedullary nail is fitted within the bone, the exact location of the through transverse holes at either end thereof is not observable to the operating physician. Therefore, means must be provided to enable the physician to locate these holes preciesly and insert threaded fastener through the bone and into and through the transverse holes. This is not an easy task. Location of the proximal transverse hole or holes is relative to location of the holes at the distal end of the nail. The through holes in the proximal end of he nail are usually located by a fixture which positions itself relative to the top and accessible end of the intramedullary nail. The top of the intramedullary nail is usually accessible because it is at this location that the surgeon cuts through he leg of a person in order to gain access to the portion of the femur or tibia where the intramedullary nail will be inserted. Since this usually occurs at the proximal end of the bones, location of the proximal transverse holes is a task of medium difficulty.
Location of the transverse holes at the distal end of the bones is another matter completely. Because the intramedullary nail is not exposed at this end of the bone and because there is no incision at this portion of the person's body, x-ray apparatus in conjunction with various fixtures must be utilized to locate these transverse holes. Usually, in the prior art, a targeting device which utilizes the proximal end of the bone as a reference location is placed in the vicinity of the distal transverse hole or holes. Then, utilizing a combination and x-rays and an imaging intensifier, the targeting device is hopefully aligned perfectly with the hole in the distal end of the bone. This is a trial and error procedure and is very difficult. Many times, a number of attempts must be made before the hole is finally located and the fastening device inserted therethrough.
Accordingly, a primary object of the present invention is to provide an intramedullary nail which will allow proper fixation of a closed, an open, or any other type of break or fracture of the femur or tibia.
Another object of the present invention is to provide an intramedullary nail which will allow for reconstruction of femoral and tibial bone fractures wherein the reconstructed bone is properly aligned as to transverse, axial and rotational aspects and provides for the proper pre-fracture length of the bone.
Another object of the present invention is to provide an intramedullary nail for the proper fixation of a broken tibia or femur bone, where the fracture involves a simple closed transverse fracture, a segmented fracture, a rotationally unstable fracture, comminuted fracture, or a fracture with bone loss.
Another object of the present invention is to provide an intramedullary nail which allows for fixation of proximal fractures of a femur bone including fractures across the neck thereof.
Another object of the present invention is to provide an intramedullary nail which allows for proper fixation of fractures of the distal end of a femur or a tibia.
The above-stated objects as well as other objects which although not specifically stated, but are intended to be included within the scope of the present invention, are accomplished by the present invention and will become apparent from the hereinafter set forth Detailed Description of the Invention, Drawings, and the Claims appended herewith.